Microstructure and fretting behavior of hard TiN-based coatings on surgical titanium alloys

An original nitriding method [powder immersion reaction assisted coating (P IRAC)] for improving wear resistance of Ti-based surgical alloys was develo ped. CP Ti and Ti-6Al-4V alloy samples were annealed in sealed stainless st eel containers that allow selective diffusion of nitrogen atoms from the at mosphere. The microhardness-microstructure and nitrogen concentration relat ionship were studied for TiN-based PIRAC coatings grown at 850-1100 degrees C. Phase identification and microstructure characterization of nitrided sa mples were performed by XRD, SEM/EPMA and HRSEM. The effect of PIRAC coatin g on fretting behavior of Ti-6Al-4V was studied in vitro under conditions s imulating in vivo conditions at the interface of modular orthopedic implant s. A significant reduction in friction coefficient and fretted areas was me asured for the coated samples. (C) 2000 Elsevier Science Ltd and Techna S.r .l. All rights reserved.